High-entropy materials (HEMs) are a novel class of materials characterized by the incorporation of at least five principal elements, resulting in four core effects: high-entropy, severe-lattice-distortion, sluggish-diffusion, and cocktail effects. Inspired by these principles, this study proposes the concept of a high-entropy solid waste-based binder (HESWB), synthesized from blast furnace slag (BFS), fly ash (FA), carbide slag (CS), red mud (RM), and desulfurization gypsum (DG). The roles of individual components in influencing strength development, hydration behavior, and pore structure were systematically analyzed. Compared to ordinary Portland cement (PC), HESWB-based concrete exhibited a 24% and 14% reduction in static elastic modulus for natural coarse aggregate and ceramsites, respectively, a more than 82% reduction in autogenous shrinkage, and almost no chloride penetration after 28 d. These improvements are attributed to the synergistic effects among the diverse components, which refine the pore structure and alter the hydration kinetics. This study not only introduces a sustainable approach for utilizing industrial solid wastes but also demonstrates the potential of HESWBs to enhance concrete durability and performance, offering promising implications for future cementitious systems.